Injection arrangement

Abstract

The invention relates to a pump unit ( 2 ), replaceably attachable to a reusable backend ( 3 ) of an injection arrangement ( 1 ) for delivering a liquid medicament, the pump unit ( 2 ) comprising a medicament inlet ( 2.1 ), a medicament outlet ( 2.2 ) and a peristaltic pump for delivering the liquid medicament from the inlet ( 2.1 ) to the outlet ( 2.2 ), the peristaltic pump comprising a pump rotor ( 2.3 ) and a pump hose ( 2.4 ), the pump hose ( 2.4 ) partially arranged around the pump rotor ( 2.3 ), the pump rotor ( 2.3 ) having protrusions ( 2.5 ) for engaging the pump hose ( 2.4 ), wherein a fixing side ( 2.6 ) of the pump unit ( 2 ) facing a reusable backend ( 3 ) when attached has a recess ( 2.7 ) in the shape of a circular arc for allowing a correspondingly shaped stop ( 3.1 ) protruding from the reusable backend ( 3 ) to enter into the pump unit ( 2 ) so as to support the pump hose ( 2.4 ) from an outer side opposite the pump rotor ( 2.3 ) thus allowing the protrusions ( 2.5 ) to locally squeeze the pump hose ( 2.4 ) against the stop ( 3.1 ) when attached to the reusable backend ( 3 ).

The invention claimed is: 
     
       1. A pump unit, replaceably attachable to a reusable backend of an injection arrangement for delivering a liquid medicament, the pump unit comprising a medicament inlet, a medicament outlet and a peristaltic pump for delivering the liquid medicament from the inlet to the outlet, the peristaltic pump comprising a pump rotor and a pump hose, the pump hose partially arranged around the pump rotor, the pump rotor having protrusions for engaging the pump hose, characterized in that a fixing side of the pump unit facing a reusable backend when attached has a recess in the shape of a circular arc for allowing a correspondingly shaped stop protruding from the reusable backend to enter into the pump unit so as to support the pump hose from an outer side opposite the pump rotor thus allowing the protrusions to locally squeeze the pump hose against the stop when attached to the reusable backend. 
     
     
       2. Pump unit according to  claim 1 , characterized in that the recess is arranged for allowing the pump hose to relax before or after being attached to a reusable backend. 
     
     
       3. Pump unit according to  claim 1 , characterized in that the pump rotor and/or the pump hose have/has an anti-stick coating. 
     
     
       4. Pump unit according to  claim 1 , characterized in that the pump rotor has an adapter for engaging a drive shaft of a reusable backend. 
     
     
       5. Pump unit according to  claim 4 , characterized in that the pump rotor is a one-part component. 
     
     
       6. Pump unit according to  claim 1 , characterized in that a flow sensor for determining a volume flow of the medicament is arranged in the pump unit and connectable to a control unit of a reusable backend. 
     
     
       7. Reusable backend for an injection arrangement for delivering a liquid medicament, comprising a medicament container, a control unit, a drive unit and an energy source, the reusable backend attachable to a replaceable pump unit, characterized in that the reusable backend comprises a stop with a circular arc profile protruding from a front side facing the replaceable pump unit when attached for entering a correspondingly shaped recess in the replaceable pump unit so as to support a pump hose of the pump unit from an outer side opposite a pump rotor of the pump unit thus allowing protrusions of the rotor to locally squeeze the pump hose against the stop. 
     
     
       8. Reusable backend according to  claim 7 , characterized in that the control unit is connectable to a flow sensor for determining a volume flow of the medicament arranged in the pump unit. 
     
     
       9. Reusable backend according to  claim 7 , characterized in that the energy source is a rechargeable accumulator. 
     
     
       10. Reusable backend according to  claim 9 , characterized in that the rechargeable accumulator is chargeable by an external charging device arranged for holding the reusable backend. 
     
     
       11. Reusable backend according to  claim 7 , characterized in that a user interface for user interaction is arranged. 
     
     
       12. Injection arrangement for delivering a liquid medicament, comprising a pump unit according to  claim 1  and a reusable backend according to  claim 7 . 
     
     
       13. Use of an injection arrangement according to  claim 12  for delivering one of an analgetic, an anticoagulant, Insulin, an Insulin derivate, Heparin, Lovenox, a vaccine, a growth hormone and a peptide hormone.